In recent years, the functions of mobile electronic apparatus typically, such as, mobile phones have been being made increasingly improved. For example, as described in the following Patent Documents, mobile electronic apparatus capable of calculating bearings based on geomagnetism detected by a geomagnetic sensor are known:    Patent Document 1: Japanese Patent Publication (A) No. 2003-289366    Patent Document 2: Japanese Patent Publication (A) No. 2005-110031    Patent Document 3: Japanese Patent Publication (A) No. 2005-107324    Patent Document 4: Japanese Patent Publication (A) No. 2005-107323    Patent Document 5: Japanese Patent Publication (A) No. 2005-300896    Patent Document 6: Japanese Patent Publication (A) No. 2005-291936    Patent Document 7: Japanese Patent Publication (A) No. 2005-291935    Patent Document 8: Japanese Patent Publication (A) No. 2005-291934    Patent Document 9: Japanese Patent Publication (A) No. 2005-291933    Patent Document 10: Japanese Patent Publication (A) No. 2005-291932    Patent Document 11: Japanese Patent Publication (A) No. 2005-291931